Hydrokinetic device

ABSTRACT

A housing is provided with two coaxial toroidal chambers which are axially adjacent one another. A stator wheel is accommodated in each of the chambers, and a rotor wheel is also accommodated in each chamber. The wheels, which are respectively symmetrically arranged, are provided with blades extending circumferentially and all inclined in the same direction. A working-fluid passage communicates with each chamber and each such passage has a oneway valve interposed in it. A common outlet duct for the working fluid communicates with both of the chambers. A connecting passage communicates the cores of the chambers with one another.

United States Patent 1191 Mueller Jan. 1, 1974 [5 HYDROKINETIC DEVICE3,512,616 5/1970 Bessiere 188/296 [75] Inventor: Helmut Mueller,Heidenheim/Brenz, FOREIGN PATENTS OR APPLICATIONS Germany 15,695 1911c1631 Britain 188/296 [73] Assignee: Voith Getriebe KG, Heidenheim,

Germany Primary Examiner-Edgar W. Geoghegan At: --M' h l S. St k 22Filed: Feb. 23, 1973 Omey ac er [21] Appl. No.: 335,122 [57] ABSTRACT Ahousing is provided with two coaxial toroidal cham- [30] ForeignApplication Priority Data bers which are axially adjacent one another. Astator Feb. 25, 1972 Germany P 22 08 857.9 Wheel is accOmmodated in eachof the Chambers, and a rotor wheel is also accommodated in each chamber.52 us. c1 188/296, 60/363, 60/364, The Wheels, which are respectivelysymmetrically 60/366 ranged, are provided with blades extendingcircumfer- 51 1m. (:1. F16d 57/02 entially and all inclined in the Samedirection A Work- [58] Field 61 Search 188/296, 290; ing-fluid passageCommunicates with each Chamber 0 344 343 3 3 3 4 3 and each such passagehas a one-way valve interposed in it. A common outlet duct for theworking fluid [56 References Cited communicates with both of thechambers. A connect- UNITED STATES PATENTS ing passage communicates thecores of the chambers with one another. 3,072,222 1/1963 Kugel et al188/296 3,48l,148 12/1969 Muller et al. 188/296 8 Claims, 3 DrawingFigures "1 J 1 I' i I A 5 ya l\ i 2 l ,5 ,2 I3

HYDROKINETIC DEVICE BACKGROUND OF THE INVENTION The present inventionrelates generally to a hydrokinetic device, and more particularly to ahydrokinetic device which is especially suitable for use as a fluidbrake.

In my prior U.S. Pat. No. 3,481,148 I have disclosed a hydrokineticdevice of the type in question, that is a fluid-flow machine which isespecially suitable as a fluid coupling as a fluid brake. The machinethere disclosed may have a pair of primary and a pair of secondarywheels, that is rotors and stators, provided with blades which areinclined on them in one or in opposite directions, and which areaccommodated in toroidal chambers.

If the just-mentioned device is used as a fluid brake, then it can beemployed with particular advantage as a brake of railway rolling stock,although its application is by no means limited thereto. However, thisis one field of application in which this type of brake has beenextensively tested and has been found highly advantageous. The brakes ofthis type are capable of producing a relatively high braking force whilerequiring relatively little space which is usually at a premium in suchapplications.

On the other hand, this type of brake has certain drawbacks. Therequirements which must be met to be able to fill the brake with brakingfluid are relatively extensive, necessitating the provision of a pumpwhich supplies braking fluid under high pressure and a correspondinglylarge-dimensioned and powerful motor for driving the pump. Both of theseunits are relatively large, due to the requirements made of them, andtherefore need a substantial amount of space over the above that whichis required by the braking device itself. In addition, these powerfulpump and motor units are of course rather expensive. Naturally this isto be considered a drawback, especially in the context of a railwayvehicle where space for the installation of such components is usuallystrictly limited. In addition, the supply of electrical energy inrailway vehicles, especially in the case of freight cars, is not usuallyable to meet the high and sudden current requirements which occur whenthe brake must operate.

SUMMARY OF THE INVENTION It is, accordingly, an object of the presentinvention to overcome the aforementioned disadvantages.

More particularly it is an object of the present invention to provide ahydrokinetic device which is especially suitable as a fluid brake andwhich avoids the aforementioned drawbacks.

Still more particularly, it is an object of the invention to providesuch an improved hydrokinetic device which requires less effort tocharge the brake with braking fluid, so that the energy requirements foreffecting such charging will be correspondingly decreased.

A concomitant object of the invention is to provide such a device which,due to its lesser charging-energy requirements, can operate fullysatisfactorily with a charging pump and associated drive motor that canbe significantly smaller than what is known heretofore.

An additional object of the invention is to provide such a device whichin many applications can even operate without a charging pump and motortherefor.

In keeping with these objects, and with others which will becomeapparent hereafter, one feature of the invention resides in ahydrokinetic device, particularly a fluid brake which briefly statedcomprises a housing having two axially adjacent toroidal chambers, and apair of symmetrically disposed stator wheels in the respective chambers,as well as a pair of similarly disposed rotor wheels which are also inthe respective chambers and which each cooperate with the associatedstator wheel. A plurality of blades is provided on each of the wheelsand all blades are inclined in the same direction. A separateworking-fluid inlet passage communicates with each of the chambers and aoneway valve is interposed in these inlet passages. A common outlet ductis provided for the working fluid, and communicates with both of thechambers. Finally, a connecting passage communicates the cores of thechambers with one another.

A hydrokinetic device constructed in this manner overcomes thedisadvantages of the prior art. It is based on the realization that thehigh power requirements of the charging pump in the prior-art devicesare caused by the arrangement of the blades on the wheels, resulting inthe application of the braking force substantially in only one of thetwo working chambers. For ease of identification these working chamberswill hereafter be identified as an active working chamber and aninactive" working chamber, meaning that while the braking force isapplied by the wheels in the active braking chamber the wheels in theinactive braking chamber contribute little if anything to the brakingforce.

In operation of the device according to the prior art the pressure atthe other circumference of the active working chamber will besubstantially higher than the inactive working chamber. Also, it appearsthat this high pressure is propagated from the outer circumference ofthe active working chamber via a cylindrical gap between the housing andthe rotor wheel, and then via the inactive working chamber to thebraking fluid supply duct which is common to both of the workingchambers. This means that the charging pump must actually operateagainst a higher head (greater back pressure) than if both of theworking chambers were uniformly active. Such operation is, however, notpossible with the prior-art device.

On the other hand, the hydrokinetic device according to the presentinvention assures that the charging pump must supply fluid only againsta very low head. There is no more pressure propagation from the inactiveworking chamber into the supply duct for incoming braking fluid. Thismeans that the charging pump must supply braking fluid only against thevery low head which is built up in that one of the separate supply ductswhich communicates with the working chamber that is active at theparticular time. It will be appreciated that a chamber which is activein one operation may be inactive in another operation of the brake. Incertain circumstances, for example if the rotor is constructed with asupply duct disposed radially inwardly of its annulus of blades andconfigurated in the same manner as the ducts of impellers ofself-priming radial pumps, the pressure of the head may actually dropbelow atmospheric pressure so that in such applications a charging pumpwith the associated motor can be completely omitted. In this case thebrake rotor itself performs the function of the pump, and of course suchconstruction is still smaller and still less expensive.

However, in order for the device according to the present invention tooperate in the desired manner and to overcome the disadvantages of theprior art, it is necessary to assure that the working fluid in thatworking chamber which is inactive at any given time, and which isblocked off by the one-way valve, will nevertheless be able to circulateso that it can become dis charged and cooled. It is for this purposethat the connecting passage communicating the cores of the chambers withone another has been provided. Thus, working fluid which has been heatedin the chamber which is inactive at a given operation, can transfer intothe active working chamber and may leave the brake from there via thecommon discharge duct. It is important, incidentally, that theconnecting passage communicate not just anywhere with the chambers butwith the cores thereof, because it is only in the core of the activeworking chamber that the pressure is sufficiently low to permit workingfluid to flow from the inactive into the active working chamber.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbest be understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING F IG. 1 is a fragmentary axial sectionthrough a device according to the present invention;

FIG. 2 shows the blades of the device of FIG. 1 in a partially developedcylindrical section taken on line Il-II in FIG. 1; and

FIG. 3 is a complete axial section through the device of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing indetail, which will be seen to illustrate a single exemplary embodimentof the novel device in FIGS. 1-3, it should be noted that the brake hasa housing through which there extends a shaft 1 which is rotatable andwhich is to be decelerated by the operation of the novel device. Thehousing is provided with two working chambers A and B which are oftoroidal configuration. The chamber A accommodates a bladed rotor wheel2 and a bladed stator wheel 4, and the chamber B accommodates a bladedrotor wheel 3 and a bladed stator wheel 5. The blades of all the wheelsare set at an angle with respect to the axis of rotation of therespective wheels, and FIG. 2 shows that they also are all inclined inone and the same direction.

Both of the chambers A and B communicate with a common fluid dischargeduct 9 through which the braking fluid is discharged from the chambers.Each of the chambers A and B is, however, provided with a separateworking-fluid inlet passage which in the case of chamber A is identifiedwith reference numeral 7 and in the case of chamber B with referencenumeral 8. The rotor wheels 2, 3 which in the illustrated embodimentinwhich they are symmetrically located between the outer stator wheels 4,-can be unitary with one another, are also provided with two rows ofrespective supply passages 10 and ll. In the illustrated embodimentthese passages 10 and 11 are constructed in the manner of impeller ductsof radial pumps, so as to provide self-priming action. Because of theprovision of the ducts l0 and 11 and of the manner in which they areconstructed, the illustrated embodiment does not require a pump forsupplying working fluid thereto, although a pump can be utilized,especially in other embodiments as will be discussed later. The passages10 and 11 are continued within the rotor wheels 2 and 3 by pipes 12 and13, respectively, which extend to the core of the respective workingchamber A and B. The term core is here intended to include the portionof the respective chambers through which a plane normal to their axis ofrotation extends, if such a plane is a plane of symmetry. In otherwords, the core includes the portion of each chamber intermediate therespective rotor and stator wheel therein. These cores are incommunication with one another'by a plurality (only one shown) ofconnecting passages 14 (see the lower portion of FIG. 3) so as to permitthe flow of fluid from that working chamber which is the inactive"working chamber at a particular time into that working chamber which atthe same time is the active working chamber. In addition, the workingchambers communicate via a cylindrical gap 15 located in the radialouter zone of the device.

Each of the working-fluid inlet passages 7 and 8 is provided within thedevice itself with a one-way valve 16 and 17, respectively, which eachhas associated with it a restoring spring 18 or 19. The valves 16 and 17permit the flow of braking fluid into the device from thenon-illustrated exterior source (which may merely be a reservoir if theconstruction is as illustrated in the drawing, or which may be a pumpdrawing from a reservoir); they prevent the expulsion of such fluid fromthe device back into the passages 7 and 8.

When the rotor wheels of the illustrated device rotate in the directionof the arrow R (see FIG. 2) then the working chamber A is the activeworking chamber whereas the chamber B is the inactive working chamber.The brake force produced in the chamber A is greater by several decadesthan that produced in the inactive working chamber B. With theconstruction illustrated in the exemplary embodiment, the active workingchamber (here the chamber A) together with its associated passages 10has a suction effect on the brake fluid. The fluid pressure which isbuilt up in the chamber A, particularly in the region of its outercircumference, is propagated via the gap 15 into the inactive workingchamber, here the chamber B, so that the brake fluid (which may be oil)would overcome the head of pressure in the inlet passage 8 and leave thedevice via this passage, were it not for the provision of the one-wayvalve 17 which prevents this. Evidently, if the rotor wheels rotate inthe direction opposite to the arrow R shown in FIG. 2, the conditionsare reversed, and it is the chamber B which is the active workingchamber, whereas the chamber A is the inactive working chamber. In thiscase the pressure would be communicated from the chamber B into thechamber A and would tend to expel working fluid through the inletpassage 7 thereof, except that this is prevented by the oneway valve 16.

Due to the suction effect provided by the passages 10 and 11 (that iswhichever passages are associated with the chamber which is at themoment the active working chamber), a charging pump is not normallyrequired with the illustrated embodiment. However, if the passages or 11were omitted or constructed in a different manner, or if it is for anyreason desired to provide such a pump, then its pressure side or outletcan be connected with the inlet passages 7, 8, as illustrateddiagrammatically in H6. 3.

It remains to be pointed out that the outlet duct 9, which is common toboth chambers A and B, communicates advantageously with a heat-exchangerwherein the braking heat which has built up in the braking fluid isdissipated. Evidently, such heat-exchangers are well known and thereforeneed not be illustrated or described. From the heat-exchanger theworking fluid is recirculated into the brake, via the pump if one isprovided, or directly (e.g., via a reservoir, if there is no p p)- ltwill be understood that each of the elements described above, or two ormore together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in afluid brake, it is not intended to be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting features thatfrom the standpoint of prior art fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is intended as new and desired to be protected by Letters Patent isset forth in the appended claims.

I claim:

1. A hydrokinetic device, particularly a fluid brake, comprising ahousing having two axially adjacent toroidal chambers; a pair ofsymmetrically disposed stator wheels in the respective chambers, and apair of similarly symmetrically disposed rotor wheels also in therespective chambers and each cooperating with the associated statorwheel; a plurality of blades on each of said wheels and all inclined inthe same direction; a separate working-fluid inlet passage communicatingwith each of said chambers; a one-way valve in each of said inletpassages; a common outlet duct for working fluid communicating with bothof said chambers; and at least one connecting passage communicating thecores of said chambers with one another.

2. A device as defined in claim 1; and further comprising a shaftextending through said housing coaxially with said chambers.

3. A device as defined in claim 1; and further comprising working-fluidsupply passages for said rotor wheels and arranged radially inwardly ofthe blades thereof.

4. A device as defined in claim 1, wherein said rotor wheels are locatedaxially intermediate said stator wheels.

5. A device as defined in claim 1, wherein said chambers are coaxialwith one another.

6. A device as defined in claim 1, wherein said chambers have identicaldiameters.

7. A device as defined in claim 1,. wherein said blades are arranged inform of annuli, each provided on one of said wheels.

8. A device as defined in claim 1; and further comprising a pump havinga discharge side connected with said inlet passage for supplying workingfluid thereto.

1. A hydrokinetic device, particularly a fluid brake, comprising ahousing having two axially adjacent toroidal chambers; a pair ofsymmetrically disposed stator wheels in the respective chambers, and apair of similarly symmetrically disposed rotor wheels also in therespective chambers and each cooperating with the associated statorwheel; a plurality of blades on each of said wheels and all inclined inthe same direction; a separate working-fluid inlet passage communicatingwith each of said chambers; a one-way valve in each of said inletpassages; a common outlet duct for working fluid communicating with bothof said chambers; and at least one connecting passage communicating thecores of said chambers with one another.
 2. A device as defined in claim1; and further comprising a shaft extending through said housingcoaxially with said chambers.
 3. A device as defined in claim 1; andfurther comprising working-fluid supply passages for said rotor wheelsand arranged radially inwardly of the blades thereof.
 4. A device asdefined in claim 1, wherein said rotor wheels are located axiallyintermediate said stator wheels.
 5. A device as defined in claim 1,wherein said chambers are coaxial with one another.
 6. A device asdefined in claim 1, wherein said chambers have identical diameters.
 7. Adevice as defined in claim 1, wherein said blades are arranged in formof annuli, each provided on one of said wheels.
 8. A device as definedin claim 1; and further comprising a pump having a discharge sideconnected with said inlet passage for supplying working fluid thereto.